Detection and elimination of termites

ABSTRACT

A bait station for use in the elimination of termites when detected comprises a hollow body having a plurality of apertures therein and occupying substantially the entire interior of the hollow body in a cellulosic matrix containing a termiticide. The bait station is adapted for attachment to a detector station or a termite infested structure via an exposable aperture by a communicator tube extending between an interior region of said bait station and an interior region of said detector station or said structure to provide a termite pathway between said cellulosic matrix and a termite colony.

FIELD OF THE INVENTION

This invention is concerned with the detection and elimination oftermites internally and externally of structures.

The invention is concerned particularly although not exclusively withmethods and apparatus for detection and/or elimination of subterraneantermites and/or termite infestations in structures.

BACKGROUND OF THE INVENTION

Termite infestation of timber structures is a worldwide problemaffecting buildings including domestic dwellings and other timberstructures such as bridges, power poles and the like.

Unfortunately most termite infestations in timber structures are notdiscovered until after extensive damage has been done to the structure,often necessitating removal of wall and ceiling claddings or floors foraccess to affected structural timber beams or members. In some cases,the extent of damage in a dwelling structure may be such that it is lessexpensive to demolish and rebuild the structure rather than attemptin-situ repairs. For other structures such as bridges, power poles orthe like, there is often no alternative other than to effect in-situreplacement. In either event, the solution to termite damage isextremely costly.

The prevalence of subterranean termite infestations is so great thatmany local authorities now require the application of a termiticidebarrier to the soil upon which a structure such as a domestic dwellingis to be erected. Originally, such termiticides included long lastingorganochlorine or organo-phosphorous compounds, but environmental andtoxicity considerations now preclude such compositions. A difficultywith chemical barriers is that approved termiticide compositions have ashort half-life as low as 90 days, and their effectiveness iscompromised by local soil and moisture conditions in many cases.

Typically, up to 500 litres of an aqueous termiticide composition isapplied to the “footprint” of the proposed dwelling before the pouringof a concrete slab or the installation of footings and piers. Thereafterat 3 to 5 yearly intervals up to 500 litres of termiticide is applied ina trench around the structure in an endeavour to maintain the termitebarrier. In some cases a reticulation system is installed under theconcrete slab, but in other cases it is necessary to drill the slab topermit introduction of a liquid termiticide thereunder. While thetermiticides used in this process are known to be effective inlaboratory tests, there is no experimental data available to supportlong term in situ effectiveness but in any event the process isenvironmentally unacceptable.

Because of the generally acknowledged ineffectuality of chemical barriersystems it has been proposed to install stainless steel mesh or crushedgranite perimeter barriers about structures such as domestic dwellings.Anecdotal evidence suggests that these physical barriers may bepartially effective only if correctly installed and maintained andotherwise not bridged or bridged.

Over the last ten years colony baiting has regained some popularity withthe development of termite detection stations. As it is known thattermites forage randomly about 50 mm below the surface of the soil in anarea of about 0.3-0.4 hectares surrounding a nest, it is possible todetect the presence of termites near a dwelling using strategicallyplaced detection stations. A typical detection station comprises aplastic cylinder with or without a collar about an access port having aremovable closure cap. The cylinder includes a softwood block accessiblevia apertures in the cylinder wall when the station is buried in thesoil with the closure cap exposed. When found by foraging termites, afeeding connection is established but this can take up to severalmonths. Once the feeding cycle is established and determined by regularviewing of the interior of the baiting station, a toxic substance mixedwith a cellulosic feed base is inserted into the baiting station orinserted into the soil adjacent the baiting station in a hollowperforated stake.

Generally speaking, the termiticides used fall into either of twogroups—a chitin synthesis inhibitor or a stomach poison. Chitinsynthesis inhibitors are hormonal in nature and prevent moulting of theexoskeleton in immature worker termites. Known chitin synthesisinhibitors include Hexaflumuron and Diflubenzuron. Ultimately, thenon-foraging termites, including the queens, soldiers and reproductives,which in any event are unaffected by the chitin synthesis inhibitors,die of starvation. This process can take several months and requiresconstant supervision and replenishment of the stakes containing thetermiticide.

The so-called “stomach poison” class of termiticides which includesulfluramid and sodium borate, directly poison termites feeding oncellulosic materials impregnated therewith. Sulfluramid is a slow actingtoxin thought to kill protozoa in the termite's gut which enabledigestion of cellulose foods. Sodium borate is typically sprayed ontoinfested timbers and works in a similar manner to sulfluramid—bothtaking from 60-90 days to kill the termites.

Colony baiting can be effective for detection and eradication oftermites externally of a structure such as a domestic dwelling providedthat sufficient bait stations are employed and that adequate and regularsupervision and replacement of baited stakes occurs. There are some“do-it-yourself” kits available for homeowners for detection anderadication of termites as these do not require the services of alicensed operator to install. However the majority of termite treatmentprocesses require the services of a licensed professional installer toinstall, monitor and maintain the termite detection and eradicationsystems.

Generally speaking, systems for detection of internal termiteinfestations are not employed unless there is evidence of or at least agood reason to suspect termite infestation. Methods for the detection oftermite infestations include non-intrusive or non-destructive tests suchas acoustic tests utilizing differing impact devices, moisture detectiondevices, acoustic emission devices such as a stethoscope or anelectronic monitoring device. Intrusive devices may include a pointedprobe, a boroscope or other optical devices inserted into a structurethrough a preformed aperture.

Once evidence of a termite infestation is located in, say, a skirtingboard, architrave or a window or door style there is available aprofessionally installed termite baiting station which is secured overthe infested site by screws or the like. The bait station comprises amoulded plastics box-like body with four side walls, a removable frontwall secured by screws and an open rear wall. After forming an enlargedaccess aperture in the timber member in which infestation is discovered,the open body is secured by mounting lugs to the surface of the timbermember around the aperture. A licensed operator then mixes a batch ofcellulosic feed such as α methylcellulose with water and an appropriatetoxin such as a chitin synthesis inhibitor or a stomach poison to form astiff paste which is loaded into the open body of the baiting station.When fully loaded, the front wall is screwed onto the body to form asealed chamber.

While generally effective for their intended purpose, such internalbaiting stations suffer a number of disadvantages. Due to the nature ofthe termiticide compounds used and the fact that a fresh batch of feedcontaining the termiticide must be mixed on site prior to sealing thebait container, only licensed operators may install the baitingstations. Moreover, as frequent inspections and refills are requiredthis is not only a costly exercise for the homeowner but the removal ofthe front cover plate at regular intervals can disturb the feeding cycleof the termite and seriously protract the treatment time required toeradicate a nest.

Accordingly, it is an aim of the present invention to provide a methodand apparatus for the detection and/or eradication of termites both insubterranean environments and in structures, which method and apparatusovercome or alleviate at least some of the shortcomings of prior artsystems.

SUMMARY OF THE INVENTION

According to a first aspect of the apparatus there is provided a baitstation for distribution of a termiticide to foraging termites, saidbait station comprising:—

a bait station for distribution of a termiticide to foraging termites,said bait station comprising:—

a hermetically sealed hollow body containing a cellulosic feedstuff anda termiticide, said hollow body having a plurality of closed aperturestherein at least one of said apertures being exposable to provide, inuse, an access port for termites to enter said hollow body, said hollowbody being adapted for a hermetically sealed mounting on a structurecontaining termites with said access port forming a pathway between aninterior cavity of said hollow body and termite pathways in saidstructure communicating with a termite colony, said bait stationcharacterized in that barrier located between said access port and saidtermiticide prevents direct access to said termiticide when said atleast one aperture is exposed.

Suitably, said cellulosic feedstuff comprises a cellulosic matrix ofparticulate material having a termiticide dispersed therein.

The cellulosic matrix may be incorporated into said hollow body as aflowable particulate material.

Alternatively, said cellulosic matrix may comprise a compressed body ofparticulate material with or without a binder.

If required, said cellulosic matrix may be present in said hollow bodyas a hydrated mass occupying substantially the entire interior cavity ofsaid hollow body.

The termiticide may be selected from any suitable termiticide includingborate compounds, chitin synthesis inhibitors, nicotinoids, phenolureas, phenol pyrazoles.

Suitably, a termite attractant composition may be incorporated in saidcellulosic matrix.

Alternatively, said attractant composition may be incorporated in abarrier layer of corrugated cellulosic material disposed between saidcellulosic matrix and an inner wall of said hollow body.

The termite attractant composition may be selected from any suitableattractant including allantoin, ellagic acid, hydroxycoumarin, urea.

The hollow body may comprise a viewing port.

If required, the viewing port may include an indicator which, in use,indicates the presence of termites adjacent thereto in said hollow body.

Preferably, said bait station is adapted for coupling to an adjacentbait station via alignable apertures in respective hollow bodies.

The bait station may be adapted for coupling to an adjacent bait stationvia a hollow conduit communicating with respective interior cavities ofsaid bait stations.

1. A bait station for distribution of a termiticide to foragingtermites, said bait station comprising:— a hermetically sealed hollowbody containing a cellulosic feedstuff and a termiticide, said hollowbody having a plurality of closed apertures therein at least one of saidapertures being exposable to provide, in use, an access port fortermites to enter said hollow body, said hollow body being adapted for ahermetically sealed mounting on a structure containing termites withsaid access port forming a pathway between an interior cavity of saidhollow body and termite pathways in said structure communicating with atermite colony, said bait station characterized in that barrier locatedbetween said access port and said termiticide prevents direct access tosaid termiticide when said at least one aperture is exposed.
 2. A baitstation as claimed in claim 1 wherein said barrier comprises acellulosic liner.
 3. A bait station as claimed in claim 1 wherein saidbarrier comprises a perforatable membrane.